Improvement in steam-balanced slide-valves



iuitrd 5ta-tra JOHN D. STEWART, or* LA PORTE, INDiANA.'

Lena-,sluwe 1v 90,887, dated .me 1, 1869.

IMPROVEMENT IN STEAM-I'ZBALANCED SLIDE-VALVES.

The Schedule refegajed to ,in these Letters Patent and making part of the Bama.

To all whomtt may concern Be it known that I, JOHN D. STEWART, of La Porte, in the county of La Porte, and'State of Indiana, have invented a newr and useful Improvement in Seats for Balanced Slide-Valves; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings,n1aking part of this specification, in which` Figure 1 is a perspective view of the chest which encloses the valve and itsseats, together with the rod for operating the valve and the steam-induction pipe;

Figure 2 is a plan or top view of the upper section of the steam-chest, showing also the glands which hold the packing imposition, which surrounds the pro jections upon the movable valve-seat;

Figure 3 is a bottom view of the same, sho\ving the lowersurface of the movable valve-seat;

Figure 4 is aplan` Qrtop view. of the lower section of the steam-chest and thev slide-valve which moves therein;

Figure 5 is a bottom view ofthe same, showing the induction and eduction-ports in the valve;

Figure 6 is a longitudinal vertical section of the valve-chest and valve, showing alsothe movable, or vadjustable upper seatof such valve;

Figure 7 is a vertical transverse section ofthe same; 'and Figure 8 is a perspective view of the adjustable valve-seat, with its projections and induction-steam ports.

Corresponding letters refer to coiresponding parts in the several figures. This invention relates to balanced slide-valves; and It consists in the combination and arrangement of such a valve, with its adjustable upper seat, and with reference to the glands, and packing for the same, as will be more fully explained hereinafter.

' A, inthe drawings, represents the upper vsection of the steam, or valve-chest, which may be rectangular', orfof any other s uitable form, its lower surfacev being provided with -a disk, or plate, the lower surface of which isilush with the' bottom of the side walls of reception of packing, as shown in figs. 6 and? of the drawings.

Bvrepresents the lower-section of the chest, which is to be of the same size and form as the upper sec.

tion, above described, and is to be provided with the usual opening for the passage of the valve-rod, and with the usual, or any approved form of stuffing-box and gland for packing suchvalve-rod.

C represents the cover of the steam-chest, which may be of the usual form, and it, together? with the' .seat formed thereon, or upon the surfaceof the cylinder. This valve may consist of a flat disk, or plate of metal, of equal thickness throughout, but having, near its ends, slots, or passages, corresponding in size and shape with the induction-steampassages inthe cylinder to which it is to be applied, they being so arranged as to admit steam alternately to each end of the cylinder, as the valve is moved for that purpose.

Upon thel under side of this valve, or upon that side which comes in contact with the lower or innerfvalv'eseat, there is to be formed a concave or otherwise suitable cavity, through which the steam is to-pass in escaping fromthe cylinder. Thev arrangement of .the above-described openings or parts is clearly shown in g. 4 of the drawings.

D represents the upper adjustable seat of the valve C', it being a disk, or plate of metal, of suitable thickness to withstand the pressure of the steam, without being sprung, or bent thereby.

Upon the upper side of this disk, or plate, there are to be formed two projections, which are to be of suicient height to extend up through the disk, or plate upon the bottom of section A of the steam-chest, and

receive thepacking and glands, as shown in figs. 6

and 7.

Through these projections and through the plate, there are to -be formed apertures, or ports for the passage oi' the steam from section A of the chest to the cylinder, which ports, or passages are to be of the same area, and be arranged the same as the ports, or passages described as being in the lower valve-seat 0r in the cylinder, so that when one ofl the apertures, or ports in the valve is directly in line with either of these apertures, or ports, the steam will pass 'directlyy to the cylinderthrough such passages.

E E represent glands, the aperture through which is to be of the form and size of the projections upon the valve-seat D, and'they are to be provided, upon theirlower or inner snufaces, with a flange, or projection, to enter the recess in the lower plate of section A, as shown at a a, in figs. 6 and 7, and bear upon and retain the packingy in its position. These glands are to be held in their places, and pressed down upon the packing, when necessary, by means of screws, which are to pass down through them, and into threaded holes' formed in the plate of section A of th steam-chest.

tact With'the ends of the adjustable seat D, and thus prevent any endwise or longitudinal movement of such seat, consequent uponits resting upon the valve C'.

G represents the valve-rod used for imparting n10- tion to thevalve in the usual manner.

H represents the pipe through which the steam passes to the chest.

a a represent thev packing which is used to prevent the passage of steam from the upper to the lower sections of the chest, around the projections upon the adjustable seat.

Having thus described my invention,

What I claim, and desire to secure by Letters Patent s- 17. The construction of the adj nstable upper valveseat, .with its projections and apertures, ari'angedsubstantiallyl as shown and described.'

coser 2. The combination of the adjustable valve-'seat D, section of steam, or valve=chest A, and valve C', substantially as shown and described.

3. The arrangement of the glands E E', packingaJ a, and adjustable. seat D, substantially vas shown and described.

4. The arrangement of the st-ops, or projections F F upon the plate of section A of the steam-chest, and at the ends of the adjustable valve-seat 1),.' substantially as shown and described.

i In testimony whereof, I-,hav`e signed my name to this specification, in the presence of two subscribing Witnesses.

JOHN D. STEWART.

Witnesses:

JOHN D. STEWART, Jr., A. T. BLIss. 

